Sharp sunlight nearly silhouettes three girls, of starkly different heights, as they sway on stage atop the hill. Their bright green skirts and red shirts billow gently as they move in front of the clear blue sky. Soft, upbeat Polynesian music emanates from speakers alongside the stage. The iPhone weather app reads 80, but with a slight breeze, it feels a few degrees cooler.

"Alooooooo-ha!" their instructor, Lisa Chang, calls into the microphone.

The performance has begun. It's hard to tell how many people are in the audience — it's a mix of people who came for the show, and passers by — but it's more than last year, which had more than the year before that, Chang said.

A few dozen dancers from Aloha and Beaverton-based school Hula Hālau 'Ohana Holo'oko'a performed at 6:30 p.m. Thursday, July 17, at Magnolia Park in Hillsboro as part of the free Springs at Tanasbourne Concerts in the Park series.

Thursday's dancers ranged in age from 4 to in the 70s, and Chang has about 100 total students, between the ages of 3 and 78, she said. Some commute from as far as Lincoln City, Seaside, and Vancouver, Wash., to attend weekly classes, which Chang started 16 years ago as a hobby and has since turned into a business.

Natalie Smith, 39, decided to learn hula a few years ago when she was planning her wedding in Maui. She loves the feeling of being in nature and engaging with people when she performs outside. Smith has been dancing with Hula for a couple years now, and the name is true of the culture, she said:

"The school of hula where everyone is family."

Classes at Hula Hālau include beginning through advanced hula, Kupuna, Tahitian dance classes and private lessons. Hula Hālau is a for-profit business with ties to the Ka'ana 'Ike A Ka 'Ohana Foundation, a nonprofit since 2009, of which Chang is the executive director.